The present invention relates generally to diving apparatus. More specifically, this invention relates to the monitoring and control of the breathing gas mixture used by divers. Even more specifically, this invention relates to the monitoring and control of the oxygen partial pressure within such a breathing mixture.
One of the most important parameters to a diver is the partial pressure of oxygen (O.sub.2) in his breathing mixture. Various analog electronic circuits currently used to monitor and control O.sub.2 partial pressure have proven to be unreliable due to circuit failures. Such failures occur without warning to the user and the user is therefore left unprotected. The diver continues to use his breathing apparatus without realizing that his O.sub.2 partial pressure is no longer being monitored and sometimes discovers a failure too late to compensate for it.
In addition, the analog monitoring circuits in use today are highly magnetic. That is, they generate easily detectable magnetic fields, an undesirable quality in certain military and clandestine uses.